Manufacture of grease compositions



Sept. 15, 1953 RfJ. MOORE ETAL MANUFACTURE OF GREASE COMPOSITIONS FiledJune 24. 1949 Patented Sept. 15, 1953 MANUFACTURE 0F GREASECOMPOSITIONSl Robert J. Moore, Oakland, and John Norton Wilson,Berkeley, Calif., assignors to Shell Development Company, San Francisco,Calif., a

corporation of Delaware Application June 24, 1949, Serial No. 101,028

18 Claims.

This invention relates to a new and improved method of making greasecompositions. More particularly this invention pertains to an improvedmethod of making wide temperature lubricating grease compositions whichare extremely stable under static and dynamic conditions.

It is well established that the quality of a grease varies substantiallywith the method of making it. Thus lubricating grease compositions madefrom identical materials but in which the method of making said greaseis varied will in one case result in a grease of excellent quality andin another case be extremely poor.

One of the most important and controlling factors in the manufacture ofa good grease is the selection of a proper base oil for the soap orgelling agent used in making the grease. For example, in the manufactureof lithium soap greases suitable for low temperature use a lightviscosity base oil must be used. However, such oils present a seriousproblem in that they present a fire hazard problem since in makinggrease an elevated temperature must be used. Also greases made fromlight oils are at times incapable of retaining the grease structure,particularly under dynamic conditions, resulting in poor lubrication ofbearing surfaces and bleeding under storage or stable conditions. lThesame problem is also presented with soaps other than lithium soaps- Veryhigh viscosity oils are also to be avoided for making greases for it isdifficult to disperse soaps in such oils inasmuch as soap fibers whichultimately govern the quality of a grease have little if any change ofgrowing to a fbrous or micelle structure in such oils so as to form agrease of good stability.

It is an object of this invention to produce greases by a novel process.Another object of this invention is to produce greases by a novelprocess which are stable under static and dynamic conditions. Anotherobject of this invention is to produce greases by a novel process whichresists bleeding. Still another object of this invention is to provide amethod of making greases having a denite micelle or soap structure.Still another object of this invention is to provide a method of makinggreases in a batch or continuous process whereby mechanically stable,non-bleeding products are produced. Still another object of thisinvention is to produce a grease of desired consistency with a minimumamount of soap.

Broadly, this invention comprises a method of making improved stablegreases involving two essential features: (1) the making of a grease 2concentrate containing from 10% to 50% gelling agent, e. g. soaps, saidconcentrate being made in any conventional Way using a highly viscousoil, the viscosity of which must be above 500 at the cold or heated onlyslightly to say 80 or 90 C. prior to or while the light oil is beingincorporated so as to form the final grease product. This feature is notonly novel from the point of view that by the process of this inventiongrease compositions can be made at low temperatures resulting in amarked saving in fuel, but results in a saving in the handling andtransporting of large quantities of material and eliminates the use ofexpensive equipment necessary for making greases. Thus, for example, agrease concentrate of this invention can be prepared, packaged andshipped to a desired destination, where it is simply admixed either atroom or slightly elevated temperature with the required amount of asuitable light oil and is ready for use.

As can be noted the essence of this invention is to prepare a greaseconcentrate using a highly viscous oil and thereafter diluting saidconcentrate with a very light oil or oily material to form the nalgrease composition. Many modifications can be made, one of which is toheat-treat the grease concentrate While it is in the gel phase until arecrystallization and consolidation of the soap crystallites intodesired ber form has been attained.

The gel phase may be defined as a two-phase system comprising solidcrystalline soap and a liquid phase consisting of either soap-oil jellyor pure oil. This gel phase forms as the grease is cooled from anelevated temperature of above 200 C. at which temperature it is in ajelly phase to a temperature where recrystallization and consolidationof soap crystallites begin to occur, that is, the gel phase. Above 200C. the soap-oil mixture may be regarded as being in a jelly phase inwhich soap and oil are in a homogeneous mass.

If the heat-treating step is involved the soap and viscous oil can beadmixed and heated to a temperature of 20D-250 C. until a homogeneousmass has been attained. Modifying agents such as antioxidants, corrosioninhibitors, etc. can be added at this point. The homogeneous greaseconcentrate is then slowly cooled to below its jelly phase but above 100C. and heat-treated in this temperature range in a quiescent state untilthe desired soap ber growth has been attained. This grease concentratewhich may contain to 50% soap can be stored, and diluted with a lightcil at a convenient time (below about 100 C.) or cooled to roomtemperature, or preferably to 80 or 90 C. and diluted with a light oilor oily material until the soap content in the nal composition Variesfrom 4 to 15% and preferably from 6 to 10%. If desired the finishedproduct can be homogenized prior to being packaged.

By a viscous oil is meant to include an oil having a viscosity of from500 at 100 F. to 2000 at 100 F. SUS and higher. The oils may be naturalor synthetic or mixtures thereof. By light oils is meant to include anysuitable liquid having a viscosity below 300 at 100 F. and may includespray oils, gas oil, light petroleum distillates, organic esters, e. g.,2-ethyl hexyl sebacate, butyl acetate, undecyl ricinoleate, butyloleate, butyl stearate, etc.; low molecular weight alkylene oxide-monohydroxyl alcohol copolymers, olefin polymers, etc. Generally, oils of 50to 300 SUS at 100 F. are suitable for use as light oils.

The gelling agents used to form the grease may be soaps of fatty acidsand/or their glycerides. The saponiable material may be fatty acidshaving from 12 to 32 carbon atoms and they may be saturated, unsaturatedor polarsubstituted fatty acids,` such as capric, lauric, myristic,palmitic, stearic, arachidic, behenic, lignoceric, myristoleic,palmitoleic, oleic, linoleic, cottonseed oil fatty acid, palm oil fattyacids, hydrogenated fish oil fatty acids, ricinoleic, erucic acids andtheir mixtures and/or their glycerides, such as lard, beef, rapeseed,palm, menhaden, herring oils, etc. Other acids may be included amongwhich are: acids produced by oxidation of petroleum oil .and waxes,rosin acids, tall oil acids, abietic acids; naphthenic acids, petroleumsulfonic acids and the like.

A particularly preferred class of saponifiable materials are the hydroxyfatty .acids and their f glycerides, such as dimethyl hydroxy caprylicacid, dimethyl hydroxy capric, hydroxy physetoleic acid, ricinoleicacid, ricinelaidic acid, 12- hydroxy stearic acid, 9,10-dihydroxystearic acid, i-hydroxy palmitic acid, linusic acid, sativic acid,lanoceric acid, dihydroxy gadoleic, `hydroxy behenic acid, quince-oilacid and the like. The preferred hydroxy fatty acids are those in whichthe hydroxy group is at least 12 carbon atoms removed from the carboxylgroup. Also, it is preferable to use hydroxy fatty acids having at leastl0 carbon atoms and up to about 32 carbon atoms and preferably thosehaving between 14 and 32 carbon atoms in the molecule. Instead of usingthe free fatty yacids containing a hydroxy radical their glycerides canbe used such as castor oil or hydrogenated castor oil or mixtures offree hydroxy fatty acids and their glycerides can be used. Mixtures ofhydroxy and non-hydroxy fatty acids can be used to form soaps.

The sapcnifying agent used to make the soap may be any oxide orhydroxide of one or several of metals selected from Groups I, II, III,IV, VI, VII and VIII. Specifically the cation of the soaps may berepresented by Na, K, Li, Cs, Ca,

Sr, Ba, Cd, Zn, Al, Pb and Co. Mixtures of soaps can be used and thesoaps can be made in situ or premade soaps can be used to form thegrease. Specific examples of preferred soaps and mixtures thereof are:lithium stearate, lithium hydroxystearate, lithium ricinoleate, lithiumsoap of hydrogenated sh-oil fatty acids, lithium soap of mixed stearicand hydroxystearic acid, sodium stearate, sodium hydroxystearate, sodiumoleate, potassium oleate, potassium rosinate, calcium stearate, caiciumhydroxystearate, aluminum stearate, aluminum soap of sh-oil fatty acids,barium hydroxystearate, barium stearate, `lithium soap of mixed stearicand hydroxystearic acids, lithium soap of mixed oleic and hydroxystearicacid, sodium soap of stearic and hydroxystearic acid; aluminum soap oflstearic and oleic acid, aluminum ricinoleate; mixed soaps of lithiumstearate and sodium stearate; mixed soaps of lithium hydroxystearateland sodium stearate; mixed soaps of lithium hydroxystearate and calciumstearate, etc. Amine soaps such as triethanolamine oleate can be used incombination with metal soaps or as the gelling agent.

Instead of using only soaps as the gelling agent, mixtures of soaps andother gelling agents, such as organic or inorganic aerogels, e. g.silica aerogels and alumina aerogels can be used.

The soap content of grease compositions of this invention may Vary overwide limits and may be as high as 50%. In practice, it is possible bychoice of suitable grease-forming lubricant bases to manufacturesatisfactory lubricating greases containing only about 10% or less byweight of the soap mixtures. Very satisfactory products are obtainedwith a total lsoap content of about 3% by weight on the finished grease.

In order more clearly to set forth the invention, reference is now madeto the accompanying drawing, which is a flow diagram illustrating amethod of producing grease compositions of this invention. It isunderstood that modifications as to equipment, its arrangement, type andkind cf materials and their proportions can be resorted to withoutdeparting from the spirit of the invention as presented in the subjoinedclaims.

Referring to the flow diagram, the invention can be carried out asfollows: Into a slurry tank l a pre-made soap or soap mixtures ormaterials used for making desired soaps and the highly viscous oil areadded through lines '2 and 3, respectively. If other additives such asoxidation and corrosion inhibitors, anti-bleeding agent,

oiliness agents and the like are added to the grease they can beintroduced into the slurry tank l through conduit 2 at a convenienttime. The oil and soap or soap-forming materials are heated to around120 C. for a time sufficient t0 drive out most of the moisture whichmight be present and is then led through conduit 4, through pump B andinto heating equipment 9 where the grease is heated to a temperature offrom 200 to 250 C. and worked until a homogeneous mixture has beenattained. This hot grease concentrate which may contain from l10% to 50%soap may be conducted into a grease storage tank 26 through lines 'I and28 and at a convenient time conducted through pump 20, and lines 2l andI2 into the final grease-forming kettle I3 where it may be admixed atroom temperature or preferably heated to about C. with a light oil(50-300 SUS at 100?) which is introduced into a kettle I3 through lineI4. The

I amount of light oil used depends upon the concentration of soapdesired in the unal grease. Generally an :amount of light oil is used sothat the iinal soap content should vary from 6% to 15% by weight. Ifdesired the hot grease concentrate may be lead directly into kettle I3through lines 'I, 28, and I5, admixed with light oil from line I4 andWorked into the final grease composition.

A` preferred embodiment of this invention is to heat-treat the greaselconcentrate prior to Working it into the final grease in kettle orvotator I3. This is accomplished by regulating the iiow of the greaseconcentrate from heating tank 9 so that by the time it reaches the timeor heat-treatment tank I0 the temperature of the grease has droppedbelow 200 C. but is above 100 C. The grease concentrate is allowed toremain in tank I0 in a quiescent state within the above temperaturerange for a time suiiicient to form the desired ber length andstructure. The heat-treated grease concentrate may then be sent tostorage tank 26 or sent to the final greaseforming kettle I3 throughpump II and line I2 and Worked into the desired grease as describedabove.

The nal grease composition may be sent to storage tank I9 through linesI6 and IB or it may be-sent directly to homogenizer '23 at a temperatureranging from room temperature to about 65 C. and then discharged throughline 24 into packing container 25. If desired, a portion of the nishedgrease from kettle I3 can be returned to slurry tank I through lines I6and 29.

To illustrate the process of making greases by this invention, aspecific example, namely, the method of making soda base grease will beherein fully described following the flow diagram.

Examplel Composition of the grease was as follows:

Components Grease Balance The acids and glycerides together with the2000 SUS at 100 F. mineral cil and the caustic solution yare introducedinto slurry tank I and heated at about 80 C. until the fatty materialshave melted. The mixture is stirred vigorously to form a slurry and thetemperature increased to above 100 C. to drive oil the water. During theheating and stirring .a modicum of dimethyl silicone can. be added ifexcess foaming occurs and the polyethylene oxide is added through line 2or 30. The slurry is then lead through conduit 4 and pump S into heatingtank 9 where the grease concentrate is heated to above 190 C. andpreferably at from 204 C. and 225 C. until a homogeneous gel has beenattained. The grease concentrate is cooled and introduced into theheat-treatment tank III where it is kept at about 160 C. for about 4hours in a quiescent state. The grease is then conducted through line 2|into storage tank 26 where the grease is allowed to cool to about 90 or100 C. then it is conducted into grease tank I3 through lines 21 and I2.At a temperature of about 80-l00 C. the remaining light mineral oil 100SUS at 100 F. viscosity) is introduced into kettle I3 through line I4and the entire mass worked until a homogeneous grease has been attained.If desired the grease -concentrate can be admixed with the light oil atroom temperature. The grease is then lead to homogenizer 23 for workinginto a homogeneous consistency and texture, after which it is packed incontainers 25. Greases compounded by the above method have excellentmechanical stability and are particularly suitable for low-temperatureoperations.

Example 2' Following the above procedure an excellent grease wasprepared in which dioctyl phthalate was used instead of the lightmineral oil.

Example 2A A lithium soap and a mineral oil having a viscosity (Saybolt)of 1000 at 100 F. were introduced into slurry tank I and the mixtureheated until a homogeneous mass was formed. The slurry was then ledthrough conduit 4 and pump 6 into heating tank 9 where the greaseconcentrate was heated to around 1GO-170 C. (1-8 hours) until lahomogeneous gel was formed. The grease concentrate was then conductedthrough lines I and 28 into storage tank 20 where the concentrate wascooled to around C. and thereafter conducted into tank I 3 through line2?. At a temperature of about 80-100 C., the remaining light mineral oil(100 SUS at 100 F.) was introduced into kettle I3 through line i4 untilthe soap content varied from 4 to 15% of the total composition and theentire mass was Worked until a homogeneous grease had been attained. Thegrease was then led to homogenizer 23 for working into a homogeneousconsistency and texture, and then packed in containers 25.

Example 3` A soda base grease composed of the ingredients of Example 1was prepared by a diierent method from that described in Example 1 andthe result was a much poorer grease. This grease Was prepared byadmixing the soap ingredients, stabilizer and all of the mineral oil(which had a blended viscosity of VSUS at 100 F.) in slurrying tank I.The slurry was then lead to heating tank 9, heat-treatment tank I0 landthen into homogenizer 23 for working and then packaged.

The three greases were subjected to the Shell roll stability test inorder to determine their mechanical stabilities. The roll stabilitytester is a simulated roller bearing and consi-sts of a 90 mm. I. D. x180 mm. long cylinder inside of which is a 5 kg. weighted roller, G10mm. diam. x 176 mm. long. The grease to be tested is placed in the freespace and the outer cylinder is rotated on its axis at R. P. M. Thegrease is worked by rolling action of the inner cylinder. The stabilityof a grease is expressed as hours of rolling before its breakdown, andthe samples prepared in the three examples behaved as follows:

To improve grease compositions made by the present method minor amountsof stabilizing agents can be added to the grease.

assassin Particularly desirable stabilizing agents which can; bea usedwith grease compositions of this invention are the alkylene. glycoland/or alkylene thiogl-'yocl polymers aswell as theirmono-esters andether polymeric derivatives. The alkylene glycol polymeric materials'can be represented by the. following. general structural formula:

wherein m and n and a are integers. Preferably the polymeric. alkyleneglycols as represented by the above general formula, should be such thatthe factor a times the number of carbon atoms Witlsdn the bracketsshould be at least 6 and more.

The polymeric alkylene glycols can be made by polymerizing'in thepresence of a ycatalyst, such as iodine, hydriodic acid and the like,ethylene, propylene, isobutylene, n-butylene oxides and/or theirmixtures. Such polymers can also be produced by reacting a monohydricalcohol with an alkylene oxide. Thus a suitable product can be made byreacting n-butanol with propylene oxide at between about 212 to 230 F.under pressure and in. the presence of an alkali catalyst.

The polymerized higher polyalkylene glycols having betWeenVZ and 6carbon atoms in the al-V kylene group are most effective as additives ofthis invention and those containing the ethylene andpropylene groups arepreferred. The average molecular'weight of the polyalkylene glycols maybe from about 200 to about '7000 and the preferred molecular weightbeing from about 1000 to. 6000.

It is desired to point out that the higher polyalkylene glycols arecomposed of mixtures of severalf polymers, for example, a polyethyleneglycol having an average molecular weight of 400 consists of variousglycols varying from a minor amount of monethylene glycol and increasingup to the pentadecaethylene glycol. Therefore, it is the averagemolecular weight which is specied and wherein the present specification,polyalkylene glycols or polyethylene glycols are referred to, they dennethe higher glycols having an average molecular weight in excess of 200and preferably in. excess of 400, those with an averagemolecular'weightl of between about 1'000 to 1500 being very eective incarrying out the present invention, Y

In lieu of the polyalkylene glycols, the ester and ether derivatives canbe used. The esters can be made from a variety of acids having between 1to about 22 carbon atoms and preferably between about 10 to 18 carbonatoms. Acids which may be used are the aliphatic, aromatic, cyclic,sulfonic acids and the like. Fatty acids and especially the higher fattyacids are preferred and include such acids as lauric, myristic,palmitic, stearic, arachidic, behenic, oleic, ricinoleic,hydroxystearic, phenylacetic, phenyl stearic acids and the like.However, such acids as naphthenic acid, oil-soluble petroleum sulfonicacids, tall oil fatty acids, aromatic acids, e. g. salicylic andphthalic acids and the like may be used to form the esters. Specificexamples of esters of this type are the polyethylene glycolmonostearate, polyethylene glycol monooleate and the like.

Ether derivatives of polyalkylene glycols may be made by anyconventional method and the aromatic ethers of polyalkylene glycolshaving the general formula thiourea derivatives, e.

whereinAr is an aromatic radicalV having atri tached thereto at least.one alkyl radical denoted. by R' having from 1 to about 8 carbon atoms.and wherein YV is a, fatty acid derivative, n, m. and a are integers asin I and q is a number se,- lected from the group consisting of zero or-1.

Minor amounts of oxidation inhibitors can be added to greasecompositions of this invention such as N-butyl paraphenylene diamine.,Also effective as. oxidation inhibitors. are alpha or betanaphthylamine, phenyl-alpha or beta naphthyh amine, alpha-alpha,beta-beta, or alpha-.beta dinaphthylamine, diphenylamine, tetramethyldiamine diphenylmethane, p. e t r ole u m alkyl phenols, and2,4-diterti'ary butyl 6-methyl phenol.

Corrosion inhibitors which are particularly apa plicable withcompositions of this invention are N-primary amines containing at least6 and more than le carbon atoms in the molecule such as. hexylamine,octylamine, decylamine, dodecyl! amine, octadecylamine, heterocyclicnitrogen containing organic compounds such as alkyl sub-e stitutedoxazolines and oxazoline salts of' fatty acids and nitrophenol.

Extreme pressure agents can be added to such grease and the preferredagents comprise esters of phosphorus acids such as triaryl,alkylhydroxy, aryl, or aralkyl phosphates, thiophosphates or phosphites,etc., neutral aromatic sulfur compounds such as diaryl suldes andpolysulfides, e. g. diphenyl sulfide, dicresol sulfide, dibenzylsulfide, methyl butyl diphenol sulfide, etc., dphenyl selenide anddiselenide, dicresol selenide, and polyselende, etc., sulfurized fattyoils or esters of fatty acids and monohydric alcohols, e. sperm oil,jojoba oil, etc., in which the sulfur tightly bound; sulfurizedlong-chain clans obtained by dehydrogenation or cracking of wax;sulfurized phosphorized fatty oils, acids, esters and ketones,phosphorus acid esters having sulfurized organic radicals, such asesters of phosphoric or phosphorus acids with hydroxy fatty acids,chlorinated hydrocarbons such as chlorinated paraflins, aromatichydrocarbons, terpenes, mineral lubricating oils, etc.; or chlori natedesters of fatty acids containing the chlorine in positions other thanthe alpha position.

Additional ingredients which can be added are anti-Wear agents such asoil-solubleurea or g. urethanes, allophanates, carbazides, carbazones,etc.; or rubber, polyisobutylene, polyvinyl esters, etc.; VI improverssuch as polyisobutylene having a molecular Weight above about 800,voltolized paraffin Wax, unsaturated polymerized esters of fatty acidsand monohydric alcohols, etc.; oiliness agents such as stearic and oleicacids and pour point depressors such as chlorinated naphthalene tofurther lower the pour point of the lubricant.

The amount of the above additives can be added to grease compositions ofthis invention in around about 0.01% to less than 10% by Weight andpreferably 0.1% to 5.0% by Weight.

Greases of this invention are applicable for general automotive uses,and are excellent aircraft greases, industrial greas'es and the like.

We claim as our invention:

1. The method of making a wide temperature grease composition comprisingadmixing an oil having a viscosity above 500 at F. SUS with agrease-forming gelling agent in an amount so that the gelling agentcomprises from 10% to about 50% of the mixture, heating until ahomogeneous non-crystalline mass has formed, cooling said greaseconcentrate to a temperature position ranges from about below 100 C.,and admixing into said grease concentrate at this temperature a lightoil having a viscosity below 300 at 100 F. SUS until the content of thegelling agent based on the total comto about by weight.

2. The method of making a wide temperature `grease compositioncomprising admixing an oil having a viscosity above 500 at 100 F. SUSwith a grease-forming gelling agent in an amount so that the gellingagent comprises from 10% to about of the mixture, heating said mixtureto a temperature above 200 C. until a homogeneous non-crystalline masshas formed, cooling said grease concentrate to a temperature below 100C. and admixing into said grease concentrate at this temperature a lightoil having a viscosity below 300 at 100 F. SUS until the content of thegelling agent based on the total composition ranges from about 5% toabout 15% by weight.

3. The method of making a wide temperature grease composition comprisingadmixing an oil having a viscosity above 500 at 100 F. SUS with agrease-forming soap in an amount so that the soap comprises from 10% toabout 50% of the mixture, heating said inixure to a temperature above200 C'.n until a homogeneous non-crystalline mass has formed, coolingsaid grease concentrate to a temperature below 100 C. and admixing intosaid grease concentrate at this ternperature a light oil having aviscosity below 300 at 100 F. SUS until the content of the soap based onthe total composition ranges from about 5% to about 15% by weight.`

4. The method as defined by claim 2 in which a small amount of anoxidation inhibitor is incorporated into the grease concentrate.

5. The method as deiined by claim 2 in which the grease concentrate isheat-treated in a quiescent state prior to being cooled to below 100 F.for dilution with a light viscosity oil.

6. The method of making a wide temperature grease composition comprisingadmixing an oil having a viscosity above 500 at 100 F. SUS with agrease-forming gelling agent in an amount so that the gelling agentcomprises from 10% to about 50% of the mixture, heating said mixtureuntil a homogeneous non-crystalline mass has formed, reducing thetemperature to a point i where recrystallization occurs but not below110 C. and maintaining the grease concentrate in this temperature rangefor from about 1 to 8 hours, cooling thereafter said grease concentrateto below 100 C. and diluting said grease with a r light oil having aViscosity at 100 F. of from 75 to 300 SUS at 100 F. until the soapcontent of the grease varies from 4 to about 15% by weight.

7. The method of making a soda soap grease which comprises forming agrease concentrate containing 10% to 50% of soda soap in a highlyviscous oil having a viscosity at 100 F. of 500 to 1000 SUS, maintainingsaid grease concentrate at a temperature of from about 160 to about 170C. for from about 1 to 8 hours, cooling thereafter said greaseconcentrate to below 100 C. and diluting said grease with a light oilhaving a viscosity at 100 F. of from 75 to 300 SUS until the soapcontent of the grease varies from about 4% to about 15% by weight.

8. The method of making a wide temperature grease composition comprisingadmixing an oil having a viscosity above 500 at 100 F. SUS with 10% to50% soda soap and from 0.01% to about 1% polyalkylene glycol and heatingsaid mixture to a temperature above 200 C. until a hornogeneous m-asshas formed, reducing the temperature to about 160 and 170 C. andmaintaining said grease in this temperature range from about 1 to 8hours, cooling thereafter said grease concentrate to below C. anddiluting said grease with a light oil having a viscosity at .100 F. offrom 75 to 300 SUS at 100 F. until the soap content of the grease variesfrom 4% to about 15% by weight. V

9. rEhe method of making a lithium soap grease which comprises forming agrease concentrate containing 10% to 50% of lithium soap in a highlyviscous oil having a Viscosity at 100 F. of 500 to 1000 SUS, maintainingsaid grease concentrate at a temperature from 160 to about 170 C. forfrom 1 to 8 hours, cooling thereafter said grease concentrate to below100 C. and diluting said grease with a light oil having a viscosity at100 F. of from 75 to 300 SUS until the soap content of the grease variesfrom about 4% to about 15% by weight. i

10. The method of making a soda soap grease which comprises forming agrease concentrate containing 10% to 50% of soda soap in a highlyviscous oil having a viscosity at 100 F. of 500 to 1000 SUS, maintainingsaid grease concentrate at a temperature of from 160 to about 170 C. forfrom 1 to 8 hours, cooling thereafter said grease concentrate to below100 C. and diluting said grease with dioctyl phthalate until the soapcontent of the grease varies from about 4% to about 15% by weight.

11. The method of making a lithium soap grease which comprises forming agrease concentrate containing 10% to 50% of lithium soap in a highlyviscous oil having a viscosity at 100 F. of 500 to 1000 SUS, maintainingsaid grease concentrate at a temperature of from about to C. for from 1to 8 hours, cooling thereafter said grease concentrate to below 100 C.and diluting said grease with dioctyl phthalate until the soap contentof the grease varies from about 4% to about 15% by weight.

12. The method of making a soda soap grease which comprises forming agrease concentrate containing 10% to 50% of soda soap and from 0.01% toabout 1% polyalkylene glycol in a highly viscous oil having a viscosityat 100 F. of 500 to 1000 SUS, maintaining said grease concentrate at atemperature of from 160 to about 170 C. for from 1 to 8 hours, coolingthereafter said grease concentrate to below 100 C. and diluting saidgrease with a, light oil having a viscosity at 100 F. of from 75 to 300SUS until the soap content of the grease varies from about 4% to about15% by weight.

13. The method of making a lithium soap grease which comprises forming agrease concentrate containing 10% to 50% of lithium soap and from 0.01%to 1% polyalkylene glycol in a highly viscous oil having a Viscosity at100 F. of 500 to 1000 SUS, maintaining said grease concentrate at atemperature of from about 160 to C. for from 1 to 8 hours, coolingthereafter said grease concentrate to below 100 C. and diluting saidgrease with a light oil having a viscosity at 100 F. of from 75 to 300SUS until the soap content of the grease varies from about 4% to about15% by weight.

14. The method of making a soda soap grease of hydroxy fatty acids ofhigh molecular weight which comprises forming a grease concentratecontaining around 50% soap and from 0.01 to about 1% polyalkylene glycolin a highly viscous tent of the grease is around 8% by weight.

15. The method of making a soda soap grease which comprises forming agrease concentrate containing 10% to 50% of soda soap in a highly'viscous oil having a viscosity at 100 F. of 500 to 2000 SUS,maintaining said grease concentrate fat a temperature of from about 160to about 170 C. for from about 1 to 8 hours, thereafter Icc'ioling saidgrease concentrate to below 100 C. and diluting said grease with a lightoil having a viscosity at 100 F, of from 75 to 300 SUS until the "soapcontent of the ygrease is from about 4% to about 15% by weight.

1:6. The method of makin'gan Ialkali metal soap grease which comprisesforming -a grease concentrate containing V10% `to 50% of 'alkali metal*soap in a highly viscous oil having a viscosity 'at 100 F. of 500 to2000 SUS, maintaining said grease concentrate at aV temperature of fromabout 160 to about 170 C. lfor vfrom about 1 to 8 hours, thereaftercooling said grease concen- 1:2 tirate tb below 100 C. and diluting saidgrease with va light oil having a viscosity atf100 *of from '15 1-,0-300sus until the soap content of the grease is from about 4% to about 15%by Weight.

'17. The method 'f making soda rsoap grease by method of claim 14 inwhich the 'soda soap lis vr'nade from a mixture of hydrogenated -'shoil'aids and hydrogenated castor oil, said hydro- Vgenated fish oil acidsbeing present in a Vpre;- dominant amount.

18. The method of `making soda soap grease by the method of claim 15Which the sode. soap is made 4from a mixture of hydrogenat'ed fish oilacids and hydrogenated castor oil, Ysaid hy'dro'genated sh oil acidsbeing present in a predominant amount land in which the light oil havinga viscosity at 100 F. of from 75 to 300 SUS is dioctyl phthalate.

ROBERT J. MOORE. lJOI-IN NORTON WILSON.

References Cited in the le of this patent UNTED 'STATES PATENTS NumberName Date 2,318,668 CalknS May 11, 1943 2,343,736 Beerbower et al. Mar.'7, 1944 2,475,589 Bondi July 12, 1949

1. THE METHOD OF MAKING A WIDE TEMPERATURE GREASE COMPOSITION COMPRISINGADMIXING AN OIL HAVING A VISCOSITY ABOUT 500 AT 100* F. SUS WITH AGREASE-FORMING GELLING AGENT IN AN AMOUNT SO THAT THE GELLING AGENTCOMPRISES FROM 10% TO ABOUT 50% OF THE MIXTURE, HEATING UNTIL AHOMOGENEOUS NON-CRYSTALLINE MASS HAS FORMED, COOLING SAID GREASECONCENTRATE TO A TEMPERATURE BELOW 100* C., AND ADMIXTURE INTO SAIDGREASE CONCENTRATE AT THIS TEMPERATURE A LIGHT OIL HAVING A VISCOSITYBELOW 300 AT 100* F. SUS UNTIL THE CONTENT OF THE GELLING AGENT BASED ONTHE TOTAL COMPOSITION RANGES FROM ABOUT 5% TO ABOUT 15% BY WEIGHT.